Let’s All Just Get Along!

It's time for Bio 101 - let's talk about symbiosis (mainly because I am constantly trying to reference it in other posts). Symbiosis is a very straightforward topic, but it is still really interesting when you find examples of it in nature.

Symbiosis is a term used by biologists (specifically ecologists) to refer to the close and often life-long interactions between two or more different species. These relationships can occur between any living thing and examples are found everywhere.

Symbiosis is divided into three specific types of relationships: mutualistic, commensal, and parasitic.

Mutualism is a relationship where both (or all) species involved benefit from the relationship. Remember yesterday's post – I told you how we have lots of bacteria living in our colon? Well our relationship with these bacteria is a mutualistic relationship. The bacteria help us break down and digest food. In exchange we provide it a safe and happy home with plenty of food and water. We are both gaining from this partnership. By far the most popular example of mutualism is between sea anemones and clownfish. Clownfish have evolved an adaptation that makes them immune to the stings of the sea anemone. When a clownfish needs to hide from a predator, it can swim deep inside the anemone for protection. In exchange, the clownfish protects the anemone from its predator, the butterflyfish.

Commensalism is a relationship where one species benefits while the other species is not affected (positively or negatively). An example of this is the relationship between the cattle egret and grazing animals. As horses, cows, sheep and other livestock trample over fields feeding, they tend to stir up a lot of insects. Knowing this, the egret follows herds of animals and eats all of the insects they stir up into the air. The egret uses the livestock for an easy dinner and the livestock leave unaffected.

The last relationship is parasitism. This is when one species benefits at the expense of another. This is a tricky relationship because parasites need to be careful that they are not so damaging that they don't allow reproduction of their own species before they kill their host species (a parasite doesn't always kill its host). Parasites also have to be smart because no species is going to just allow itself to be exploited. Parasites need to be able to handle fighting off immune responses and other protective mechanisms of the host species. A popularly known human parasite is the tapeworm. Ugh, worms gross me out so I am not even going to talk about them.

Scientists did what scientist do best and broke down these main categories even more, but this is the basics. A nice easy little hump day treat!